Top 50 Databricks Interview Questions and Answers

What is Databricks?
Databricks is a cloud-based platform for big data analytics and machine learning, built on Apache Spark.
What are the main features of Databricks?
Features include collaborative notebooks, autoscaling clusters, MLflow for machine learning, and seamless integration with cloud services.
What programming languages are supported in Databricks?
Databricks supports Python, R, Scala, SQL, and Java.
What is a Databricks workspace?
It’s an environment that allows users to organize and collaborate on projects, notebooks, libraries, and dashboards.
What is a Databricks cluster?
A set of virtual machines used for executing notebooks or jobs. Clusters can be interactive or automated.

What is Apache Spark?
Apache Spark is an open-source distributed computing system for big data analytics.
How does Databricks optimize Apache Spark?
Through features like the Databricks Runtime, Delta Lake, and auto-tuning capabilities.
What is Databricks Runtime?
It’s a version of Apache Spark optimized for performance, security, and compatibility with Databricks.
What are the main components of Apache Spark?
Spark Core, Spark SQL, Spark Streaming, MLib, and GraphX.
How do you connect Databricks to an external Spark cluster?
Use the Databricks Connect tool.

What is Delta Lake in Databricks?
Delta Lake is an open-source storage layer that brings ACID transactions to Apache Spark.
What are the benefits of using Delta Lake?
Features like ACID transactions, schema enforcement, and time travel for historical data.
How do you handle schema evolution in Delta Lake?
Use the MERGE statement or enable schema auto-evolution.
What is a Databricks job?
A job is a way to run code, typically in a notebook or a script, on a Databricks cluster.
How do you schedule jobs in Databricks?
Use the Databricks Jobs UI or integrate with external schedulers like Apache Airflow.

What is Databricks SQL?
It’s a platform for running SQL queries on data in Databricks.
How do you create a table in Databricks SQL?
Use CREATE TABLE or CREATE DELTA TABLE.
What is the difference between managed and unmanaged tables in Databricks?
Managed tables store data in the Databricks filesystem, whereas unmanaged tables link to external data sources.
How do you optimize a table in Databricks?
Use commands like OPTIMIZE and VACUUM.
What are Z-Orders in Databricks?
A data clustering method used to improve query performance on Delta tables.

What is MLflow?
An open-source platform for managing the machine learning lifecycle.
How does Databricks support MLflow?
MLflow is integrated into Databricks for experiment tracking, model packaging, and deployment.
How do you train a machine learning model in Databricks?
Use libraries like TensorFlow, PyTorch, or Scikit-learn in Databricks notebooks.
What is AutoML in Databricks?
A tool for automatically training and optimizing machine learning models.
How do you deploy a model in Databricks?
Use MLflow’s model registry and deploy it as a REST API.

How do you improve cluster performance in Databricks?
Use autoscaling, enable optimized configurations, and use Databricks Runtime.
What is the Photon engine in Databricks?
A query engine that improves the performance of analytics workloads.
How do you optimize Delta Lake performance?
Use Z-Ordering, optimize files, and manage partitions effectively.
What are broadcast joins, and how are they used in Databricks?
A type of join where smaller data is broadcasted to all nodes, reducing shuffle.
What is caching in Databricks, and how does it help?
Temporary storage of frequently accessed data in memory to improve query speed.

How is security implemented in Databricks?
Through role-based access control (RBAC), encryption, and network security.
What is Unity Catalog?
A unified governance solution for managing access to data and AI assets in Databricks.
How do you encrypt data in Databricks?
Enable encryption at rest and in transit through cloud-specific configurations.
What is cluster isolation in Databricks?
Isolating clusters for enhanced security and resource management.
How do you audit user activity in Databricks?
Use audit logs available in the admin console.

How do you integrate Databricks with Azure Data Lake?
Use Azure Active Directory for authentication and mount the lake as a storage account.
How do you connect Databricks to AWS S3?
Configure IAM roles or access keys for authentication.
What is a Databricks Partner Connect?
A feature that simplifies the integration of third-party tools like Tableau and Power BI.
How do you ingest data into Databricks?
Use Databricks Auto Loader, COPY INTO, or notebooks.
What are Databricks connectors?
Pre-built integrations for connecting to databases, cloud services, and BI tools.

What are Lakehouse architectures in Databricks?
A combination of data lakes and data warehouses for unified analytics.
What is Databricks Autoloader?
A tool for automatically ingesting and processing data from cloud storage.
What is the difference between RDDs, DataFrames, and Datasets in Spark?
RDDs are low-level objects, DataFrames are optimized for SQL, and Datasets are typed versions of DataFrames.
How do you implement streaming in Databricks?
Use Spark Structured Streaming with Delta Lake.
What is a checkpoint in Spark Streaming?
A mechanism for fault tolerance and stateful streaming.

How do you migrate a Hadoop workload to Databricks?
Use the Databricks Runtime for Apache Hadoop.
How do you handle large-scale data in Databricks?
Use Delta Lake, optimize partitions, and scale clusters appropriately.
What steps would you take to debug a failing Databricks job?
Check the job logs, driver logs, and executor logs.
How do you monitor Databricks cluster performance?
Use the Databricks metrics dashboard and Spark UI.
How do you integrate Databricks with CI/CD pipelines?
Use Databricks CLI and REST API with tools like Jenkins or Azure DevOps.